Liquid dispenser



Sept. 11, 1962 D. F. coRsETTE LIQUID DISPENSER Filed March 28. 1960 INV ENTOR ATTORNEY5 Filed .Malz 28, 1960, Ser. No. 18,024 Claims. (Cl. 239-337) This invention relates to new and improved plastic dispensers of the reciprocating piston type for discharging liquids from portable containers in the form of a ne spray or mist.

It has long been the practice to employ, for the dispensing of liquids from small containers, hand actuated ptunps formed of moldable plastic material comprising, in assembled relation, a stationary unit including a barrel or cylinder for direct association with the container, and a 'reciprocable unit including a plunger or piston reciprocable in the stationary unit to effect discharge of the container contents, and having at its upper end a discharge head from which the fluid is expelled.

It is an object of the invention to effect substantial simplication of such dispensers and of methods of making and assembling the same by (1) reducing the number of component parts in each of the basic units of the dispenser, (2) altering the structural relationship of the parts to facilitate the formation during the casting operation of the necessary iluid passages, and (3) assembling component parts without the use of bonding agents.

In the application of the invention to dispensers functioning to discharge iluids in the form of a line spray or mist, and in which the discharge head and plunger are separately formed, it is an object to provide at the 4interface between the discharge head and plunger the swirl passages and spin chamber which impart rotation to the fluid in order to form fine droplets which readily disperse in air at the point of discharge.

More specically, an object of the invention is the provision of swirl passages on that external surface of the plunger on which the discharge head seats, whereby the molding of the passages can be effected quite simply and without the use of complex collapsible mold parts.

The invention is preferably, although not necessarily, applied to dispensers of the character described having means for temporarily locking the stationary and reciprocable units together in a position in which the dispenser is completely sealed, thereby preventing leakage of liquid from the container during shipping, even though the container be inverted. The invention is accordingly illustrated in the accompanying drawings in conjunction with such dispensers.

Further objects and features of the invention will be apparent from the following description, taken in connection with the accompanying drawings, in which FIGURE 1 is an enlarged longitudinal sectional view of a dispenser of the type described illustrating the application thereto of the inventive principle;

lFIGURE 2 is a front elevation of the upper end of the discharge head of the dispenser shown in FIGURE 1;

FIGURE 3l is an elevation of the upper end of the plunger or piston portion of the reciprocable unit shown in FIGURE 1, and

FIGURE 4 is a view in plan of FIGURE 3.

To promote an understanding of the invention, reference will now be made to the preferred embodiment thereof illustrated in the accompanying drawings, and specific language will be used to describe the same. It will nevertheless be appreciated that no limitation of the scope of the invention is thereby intended, such further modifications and alterations being contemplated as would normally occur to one skilled in the art to which the invention relates.

Patented Sept. 11, 1962 Referring first to FIGURE 1, the dispenser there illustrated includes a stationary unit which may be molded in one piece to provide a barrel or cylinder 12 from which Ya suction tube 13 depends and, at the upper end of the barrel 12, a collar portion 14, noting that throughout the following description the dispenser will be assumed to occupy the upright position in which it is normally used.

The upper end of the barrel 12 is preferably slotted at rcircumfere'ntially spaced points, as indicated at 18, for the purpose of preventing the formation of an airlock in the barrel 12 above the piston, to permit `ingress to the container of air in order to replace discharged liquid, and to allow drainage into the container of liquid which may pass the piston and which would otherwise be trapped in the upper portion of barrel 12.

A radial annular flange 20, formed on the collar portion 14, provides a seat for container cap 21. Cap 21 is apertured to receive collar portion 14 and is internally threaded as shown at 2.2 for cooperative engagement with external threads formed on the neck of the container; 'a gasket 24 may be positioned beneath ilange 20.

The collar portion 14 is further provided at its upper end with an exteriorly threaded sleeve portion 25, and an annular lip 30 which is formed by deformation of sleeve portion 25 after assembly of the container cap 21 thereon, in order to lock the cap on the collar portion 14.

The stationary and reciprocable units of the dispenser may be formed of any moldable plastic materials, preferably materials commonly designated thermoplastics, for instance, polyethylene and polypropylene. Vinyl chloride acetate is also highly eective, and in general, any plastic material subject to hot or cold flow, capable of being molded, and readily deformed after molding in response to heat and/ or pressure may be employed.

The reciprocable unit of the dispenser comprises a plunger 35 and a dependent hollow piston 36, the piston being enlarged in diameter at its lower end to fit snugly the interior wall of barrel 12; the plunger and piston may be integrally formed by injection molding.

The interior of plunger 35 defines a iluid passage 40, communicating at its upper end with a passage 41 which is provided with a valve seat 48 receiving a ball valve 45. Movement of fluid upwardly in the passages 40, 41 is thus normally unimpeded, the valve 45 serving merely as a check valve to prevent downward movement of fluid. At its upper end, the plunger 35 is preferably tapered upwardly to provide a conical portion 38. A discharge head 37, preferably cast separately, from thermoplastic resins of this type hereinbefore described, is recessed internally for reception with' a snug lit on the upper end of the cylindrical portion of the plunger 35 and on the tapered portion 38 thereof. Assembly of the head '37 on the plunger 35 is effected by applying endwise pressure to force the head downwardly on the plunger until it assumes the position shown, in which annular beads 39 on the plunger seat in coacting annular grooves in the interior of the head, the head yielding sufficiently to pass it over the beads. The head and plunger, thus assembled, are fitted together sutciently tightly to prevent egress of iluid therebetween. I

The tapered portion 38 of the plunger 35 terminates short of the upper end of the head 37, providing a cavity 70, into which passage 41 opens. A studr 71, projecting downwardly from the linger rest portion 73 of the head into cavity 70 serves as a retainer -for the ball valve 45.

Received within piston 36 and seated in the lower end of barrel 12 is a coil compression spring 52, actingwto urge the reciprocable unit upwardly. Ball valve 55; seating by gravity in the lower end of barrel 12acts as a check valve to p revent drainage of liquid downwardly from the` barrell 12, Preferably the seat 56 forjball valve 55 forms an angle of at least 45 with the axis of the dispenser to minimize the possibility of wedging of the valve in its seat.

Spring 52 is formed with convolutions 60 of reduced diameter, preferably adjacent each end, as shown, to provide reversibility. In the position which the parts occupy in FIGURE 1, the reciprocable unit being fully depressed, the ball valve 55 is engaged by the adjacent small convolution 60 of spring S2 to hold the valve tightly against its seat, thus preventing flow of liquid into the barrel and outwardly through passages 40 and 41 when the dispenser is inverted.

At its lower end the head is `formed to provide a depending skirt portion 42, formed with interior threads which coact with the external threads on the sleeve portion 25 of the barrel 12. When the head is thus screwed down on the upper end of the barrel, as shown in FIG- URE l, coacting inclined surfaces 62 on the head and barrel are pressed together to form a seal preventing discharge of liquid Ifrom the container through the slots 18 and externally of the plunger 35. Since movement of liquid upwardly into the lower end of the barrel 12 and the plunger 35 is prevented in the fully depressed position of the plunger by direct engagement of the convolutions 60 of the spring 52 with the ball valve 55, leakage of liquid is prevented during handling and shipping, this being of particular importance when toxic liquids, such as insecticides, are used. It should be noted that the lip 44 depending within the skirt portion 42 of the head 37 seats inside the upper end of the barrel and thus tends to resist springing of the skirt 42 and stripping of the threads as the head is screwed down on the barrel.

It will be appreciated that in order to render the dispenser operative, it is only necessary to unscrew the head from the barrel, whereupon the plunger 35 is raised by spring 52. Liquid may then lbe forced upwardly Within the plunger 35 by finger pressure on the upper surface of the head to reciprocate the plunger in barrel 12 in the usual manner.

The reciprocable unit is retained in position in the stationary unit by an inwardly directed annular part 66 which extends into close proximity with the plunger 35 and serves as a bearing surface for guiding the plunger during reciprocation thereof, while limiting outward movement of the plunger in response to the action of spring 52. The annular part 66 is formed after assembly of the two units, by assembling around plunger 35 a cylindrical tool, the tool being pressed downwardly against a shoulder formed at the junction of the barrel proper with the collar portion 14 of the barrel so as to cause the material to flow inwardly.

It will be appreciated that the sequence of steps employed in swaging or deforming the stationary unit to provide the annular lip 30 and to form the inwardly directed part 66 as described is not critical and may be reversed if desired. These steps do not ordinarily require the heating of the parts to be deformed, but where the nature of the material is such that heat is needed, it may be supplied by heating the tools employed to exert pressure on the parts.

As hereinbefore indicated, an important feature of the invention resides in the manner in which provision is made for rotating the discharging fluid as it emerges from the head, whereby droplets of fluid are dispersed in air to produce a fine mist or a spray. The achievement of effective rotation has heretofore been a substantial factor in the expense of producing dispensers of both the pump and the pressurized types, the more common method involving the use of small orifice disks, having whirl passages and spin chambers formed therein, separately formed and assembled. In accordance with the instant invention, rotation is imparted to the fluid at the interface of the plunger and head, eliminating the expense of producing and assembling a separate orifice disk. In addition, the specific construction herein disclosed is such as to reduce clogging of the ne whirl 4 passages and to eliminate certain assembly problems, orientation of the head with respect to the plunger being unnecessary because of the unique arrangement of whirl passages and associated paths provided for fluid flow.

This feature will now be described in detail.

The external surface of the tapered portion 38 of the plunger 35 is cast, as shown more clearly in FIGURE 3, to provide an annular groove 75, and a plurality of circumferentially spaced helical grooves 76. Since the tapered portion of the internal surface of the head 37 fits snugly the external surface of the tapered portion 38 of the plunger, grooves 76 form passages affording cornmunication between cavity and annular groove 75. It will be noted that grooves 76 enter annular groove 75 in a generally tangential direction. Consequently fluid under pressure in cavity 70 is directed into annular groove in such manner as to promote fluid flow in one direction in the latter (counterclockwise as viewed in FIG- URE 4), and grooves 76 and 75 thus function as swirl passages.

Formed in the inner tapered surface of head 37 is a spin chamber 80, which may be generally conical with its flared end inward. Groove 75 communicates with spin chamber 80 at one side of the latter, discharging fluid into the chamber generally tangentially of the latter. Thus the discharging fluid is caused to rotate around the axis of the chamber. An orifice 81 enters the chamber axially; fluid is expelled from the chamber through the orifice 81 as a fine jet which expands radially on leaving the orifice owing to its rotation, which is continued in the outwardly flaring discharge cones 82 and 83, of conventional design.

The simplicity of the construction and the ease with which it can be formed by the usual injection molding procedure are at once apparent. The effectiveness of the structure in forming a fine dispersion of fluid, owing to the high rotational speeds developed in the groove 75 and spin chamber 80, is equal to or greater than that developed in much more expensive spray heads.

Although the use of a conical interface `between the plunger and head has a number of advantages, it will be appreciated that the same principles are applicable to structures in which the interface is cylindrical.

While the invention has been described in its application to a pump type sprayer, its utility with self propelled fluids in a pressurized container is obvious. In such a package, the spray head is fitted on a stem extending from the top of the package, being fitted on the stern in the manner hereinbefore described, so as to provide the swirl passages and spin chamber at the interface between the stem and the head.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

l. In a fluid dispenser of the character described, the combination with a plunger having a fluid passage therein opening through its upper end, a discharge head having a recess therein in which the upper end of said plunger is received with a tight fit, the engaged surfaces of said plunger and head defining a surface of revolution, at least one of said engaged surfaces being recessed to provide at the interface between said plunger and said head a spin chamber, said plunger having an annular groove extending circumferentially thereof in a common plane, said groove extending across the peripheral edge of and in tangential communication with said spin chamber, said head having a cavity communicating with the fluid passage in said plunger, said plunger having in its said engaged surface a plurality of helical grooves extending between said cavity and said annular groove in a direction such that fluid delivered thereby to said annular groove is caused by all of said helical grooves to flow in the same circumferential direction in said annular groove, said head being provided with a discharge orifice communicating with the axis of said spin chamber.

2. In a fluid dispenser of the character described, the

combination with a plunger having a fluid passage therein opening through its upper end, a discharge head having a recess therein in which the upper end of said plunger is received with a tight lit, the engaged surfaces of said plunger and head dening a surface of revolution, at least one of said engaged surfaces being recessed to provide at the interface between said plunger and said head a spin chamber and means affording communication between the said iiuid passage in said plunger and said spin chamber, said engaged surfaces being in fluid-tight engagement with each other below said spin chamber throughout their entire circumferences said last named means including a plurality of helical grooves formed in the said engaged surface of said plunger and so directed as to promote Huid flow circumferentially of the plunger and into said spin chamber, said head being provided with a discharge oriiice communicating with the axis of said spin chamber.

3. In a fluid dispenser of the character described, the combination with a plunger having a fluid passage therein opening through its upper end, a discharge head having a recess therein in which the upper end of said plunger is received with a tight fit, the engaged surfaces of said plunger and head delining a surface of revolution, at least one of said engaged surfaces being recessed to provide at the interface between said plunger and said head a spin chamber, an endless circumferential passage extending across one peripheral edge of and in tangential communication with said spin chamber, and a plurality of helically arranged passages affording communication between the said uid passage in said plunger and said circumferential passage, said helical passages all leading in the same generally tangential direction into said circumferential passage to promote fluid iiow in one direction in the latter, said head being provided with a discharge orifice communicating with the axis of said spin chamber.

4. In a fluid dispenser of the character described, the combination with a tubular plunger having a fluid passage therein opening through its upper end, a discharge head having a recess therein in which the upper end of said plunger is received with a tight n't, the engaged surfaces of said plunger and head defining a surface of revolution, at least one of said engaged surfaces being recessed to provide at the interface between said plunger and said head (1) a spin chamber, (2) a circumferential passage in a radial plane with respect to said surface of revolution, said passage leading tangentially into and from said spin chamber, and (3) means directing uid from the said fluid passage in said plunger into said circumferential passage so as to cause unidirectional flow in the latter, said head being provided with a discharge orifice communicating with the anis of said spin chamber, said engaged surfaces being in huid-tight engagement with each other Ibelow said spin chamber throughout their entire circumferences.

5. In a dispenser for discharging liquid from a container, the combination with a stationary unit comprising a cylindrical barrel having means for attachment to a container, of a reciprocable unit comprising a plunger having at its lower end a piston slidably received in said cylindrical barrel, a discharge head having a recess in which the upper end of said plunger is received with a tight lit, said plunger, piston, and head portion having communicating passages for the discharge of fluid from said container on depression of said reciprocable unit, certain of said communicating passages being formed by recessing at least one of the engaged surfaces of said plunger and head to provide at the interface between said plunger and said head (1) a spin chamber, (2) a circumferential passage encircling said plunger and leading tangentially into and from said spin chamber at tangentially aligned points, and (3) means directing fluid from the said fluid passage in said plunger into said circumferential passage so as to cause unidirectional iiow in the latter, said head being provided with a discharge orifice communicating with the axis of said spin chamber.

References Cited in the le of this patent UNITED STATES PATENTS 2,119,884 Lohse June 7, 1938 2,362,080 Martin Nov. 7, 1944 2,389,053 Hobbs et al, Nov. 13, 1945 2,702,957 Cooprider et al. Mar. 1, 1955 2,789,012 Bretz Apr. 16, 1957 2,906,461 Bretz Sept. 29, 1959 2,989,251 Abplanalp et al June 20, 1961 

